During his freshman year at UConn, Walker played in every game and was named to the Big East All-Rookie Team. He helped the Huskies achieve a number one seed in the 2009 NCAA Tournament. Despite starting in only two games he averaged 25.5 minutes per game, far more than any regular non-starter.[6] He also helped the Huskies go to the 2009 Final Four with a 23-point effort in the Elite Eight vs Missouri.[7]

Walker played and started all 34 games in 2009–10 season. He contributed 14.6 points per game and led the Huskies in scoring for the eighth time in the last nine games of the season with 18 points at Virginia Tech. Walker was named First Team USBWA All-District. Connecticut earned a 4 seed in 2010 National Invitation Tournament, but fell short to Virginia Tech as the Huskies finished a disappointing season going 18–16 (7–11) in conference play.[8]

Walker rose to national prominence in his junior year, twelve games into his junior campaign, Walker was the nation's leading scorer, averaging 26.7 points per game. In addition, he averaged five rebounds and 3.8 assists per game. Walker appeared on one of the six regional covers Sports Illustrated.

In the 2011 Big East Tournament (during his junior year), Walker hit the game winning shot as time expired to beat #3 overall Pittsburgh and advance UConn to the semifinals. He led UConn to victory over University of Louisville in the Big East Championship game and was named MVP for the tournament. Walker scored 130 points in five games, a Big East Tournament record and the most points scored in any conference tournament in the past 15 seasons. UConn became the first school to win five games in five days to earn a conference championship.[9]

Walker announced that he would leave UConn to enter the 2011 NBA draft on April 12. Walker was selected 9th overall in the 2011 NBA draft by the Charlotte Bobcats.[17] Walker signed a multi-year shoe deal with Under Armour, the first rookie from the 2011 Draft Class to do so.[18]

On December 9, 2013, Walker scored 31 points, with 27 points coming in the second half, and scored the final 15 points to help the Bobcats defeat the Golden State Warriors, 115–111.[24] On December 18, 2013, he hit a buzzer-beating jump shot over Jonas Valančiūnas in overtime to beat the Toronto Raptors. He finished the night with 26 points and 5 rebounds on 10/18 shooting from the field.[25] On February 19, 2014, Walker recorded 24 points, 5 rebounds and a career-high 16 assists in a 116–98 win over the Detroit Pistons.[26] Five days later, he was awarded the Eastern Conference Player of the Week. He averaged 22.5 points, 8.8 assists, and 5.5 rebounds during the week. In a home victory against the Orlando Magic on April 4, 2014, Walker recorded his second career triple-double with 13 points, 10 assists, and 10 rebounds.

Walker had a stellar game four in the Eastern Conference Playoffs first round against the Miami Heat with teammate Al Jefferson unable to play due to a Plantar fasciitis injury. He finished the game with a playoff franchise high 29 points along with 5 assists, 5 rebounds, 3 blocks, and 2 steals. The effort came in a loss as the Heat completed a four-game sweep of the Bobcats.[27]

In the newly renamed Charlotte Hornets' opening game against the Milwaukee Bucks on October 29, Walker led an impressive comeback in an overtime 108–106 victory. The Hornets were 24 points down by the fourth quarter before staging a comeback; Walker scored a three-point shot with 1.6 seconds remaining to force overtime before hitting the game winning shot as well. He finished the game with 26 points, 5 assists and 6 rebounds.[28] The following day, he signed a four-year, $48 million contract extension with the Hornets.[29][30] On December 5, 2014, Walker hit his second game-winner of the season in a 103–102 win over the New York Knicks.[31] On December 27, in a 94–102 loss to the Orlando Magic, he scored a then career-high 42 points, and set a franchise record for most points scored in a half in Charlotte Hornets franchise history with 35 in the second half.[32] On January 3 against the Orlando Magic, Walker scored 30 points to pass Kendall Gill for 10th place on the Charlotte Hornets all-time scoring list with 4,160 points.[33] In three games played between January 3 and January 7, Walker scored 30 points in a win over the Orlando Magic, 33 points in a win over the Boston Celtics, and 31 points in a win over the New Orleans Pelicans to become one of four players (Larry Johnson, Glen Rice and Kelly Tripucka) in Charlotte Hornets' franchise history to ever put together a consecutive span of three or more 30-point plus games.[34] Walker also hit his fifth game winner of his career and his third game winner of the season on January 7 in the 98–94 win over the Pelicans.[35] On January 12, he was named the Eastern Conference Player of the Week for games played Monday, January 5 through Sunday, January 11. Over the week, he led the Hornets to a 4–0 record and averaged 30.3 points, 5.8 rebounds and 4.5 assists in 36.2 minutes, while shooting .500 from the field (44–88), .364 from beyond the three-point line (8–22) and .893 from the free-throw line (25–28).[36]

On January 28, 2015, Walker was ruled out for six weeks after he underwent successful surgery to repair a torn lateral meniscus in his left knee.[37] He returned to action on March 11 after missing 18 games to score six points in 16 minutes off the bench as the Hornets lost to the Sacramento Kings, 106–113.[38]

On November 23, 2015, Walker scored a then season-high 39 points in a 127–122 overtime win over the Sacramento Kings.[39] On January 18, 2016, Walker set a career-high and a franchise-record with 52 points in a 124–119 double overtime win over the Utah Jazz. He made 16-of-34 from the field, including 6-of-11 three-pointers, and was 14-of-15 from the free throw line, breaking the team mark of 48 points set by Glen Rice in March 1997.[40] On March 9, in a win over the New Orleans Pelicans, Walker became just the third Hornets player to make 500 career three-pointers, joining Dell Curry (929) and Glen Rice (508).[41] Five days later, he earned his fourth career Player of the Week award, and second of the 2015–16 season (first coming on January 25),[42] becoming just the sixth Charlotte player to win the award multiple times in the same season.[43] The Hornets finished the regular season as the sixth seed in the Eastern Conference with a 48–34 record. In the first round of the playoffs, the Hornets faced the third-seeded Miami Heat, and in a Game 4 win on April 25, Walker scored a playoff career-high 34 points, helping the Hornets tie the series at 2–2.[44] He topped that mark in Game 6 of the series, scoring 37 points in a 97–90 loss, as the Heat tied the series at 3–3.[45] The Hornets went on to lose Game 7, bowing out of the playoffs with a 4–3 defeat.

On November 4, 2016, Walker scored a season-high 30 points in a 99–95 win over the Brooklyn Nets, helping Charlotte improve to 4–1 for the first time since 2000.[46] He topped that mark on November 11, recording 40 points, 10 rebounds and six assists in a 113–111 loss to the Toronto Raptors.[47]

Walker is the son of Paul and Andrea Walker.[48][49] His mother is a Crucian, raised in Antigua of Antiguan parentage, and his father is Antiguan. He has two brothers Akil and Keya and one sister Sharifa.